In Europe, endowments of tight gas resources are thought to be in the Ukraine and Hungary; shale gas in Germany, Poland, Romania, Sweden, Denmark, the UK and France; and coal bed methane in the Ukraine and Germany.

Europe is the world's second-largest natural gas market and demand is continuing to rise, particularly as a preferred fuel for power generation, while the "Shale Gas Revolution" in the United States has changed the North American energy landscape.

Natural gas deposits are categorized as conventional if they are contained in porous reservoirs, often in limestone or sandstone, which have interconnected spaces that allow the gas to flow freely in the rock and through well boreholes. Unconventional reserves are situated in rocks of low permeability, which makes the gas difficult to access.